Genetic Assemblies Inc. proposes the development of an error filter for the elimination of errors introduced during the synthesis of oligonucleotides and longer DNA fragments. This filter is a critical enabling technology for an Automatic Gene Synthesizer (AGS), a project now under development at Genetic Assemblies Inc. (GA). The goal of the AGS is to produce user-defined DNA fragments of up to 10,000 bp in length, in less than 24 hours and with essentially no introduced errors. The error filter will be integrated with the massively parallel, light-directed DNA synthesis technology of the existing Maskless Array Synthesizer (MAS) and a light-directed oligonucleotide release chemistry developed by GA founders at the University of Wisconsin-Madison, and licensed to GA. Specific aims for the project include: attachment of an error binding protein to a solid support, determination of binding capacity and optimal binding conditions of the error filter, and determination of the optimal error filtering methodology. The ability to produce error-free long DNA fragments will revolutionize the field of molecular biology. It will allow the production of custom designed DNA for uses in protein engineering, DNA vaccines, gene therapy, and other research related to improving human health. This ability will significantly reduce the scientific community's reliance on large collections of cloned DNA fragments now used in genetic research, since almost any DNA of known sequence could be synthesized on demand. This technology will greatly accelerate the pace of genetic research and lead to the development of new drugs, treatments for genetic diseases and advanced genetic technologies.